cpufreq: Implement light weight ->target_index() routine

Currently, the prototype of cpufreq_drivers target routines is:

int target(struct cpufreq_policy *policy, unsigned int target_freq,
		unsigned int relation);

And most of the drivers call cpufreq_frequency_table_target() to get a valid
index of their frequency table which is closest to the target_freq. And they
don't use target_freq and relation after that.

So, it makes sense to just do this work in cpufreq core before calling
cpufreq_frequency_table_target() and simply pass index instead. But this can be
done only with drivers which expose their frequency table with cpufreq core. For
others we need to stick with the old prototype of target() until those drivers
are converted to expose frequency tables.

This patch implements the new light weight prototype for target_index() routine.
It looks like this:

int target_index(struct cpufreq_policy *policy, unsigned int index);

CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it. Because CPUFreq core now requires to call routines
present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time.

This also marks target() interface as deprecated. So, that new drivers avoid
using it. And Documentation is updated accordingly.

It also converts existing .target() to newly defined light weight
.target_index() routine for many driver.

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>

1 files changed, 14 insertions, 40 deletions

diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 600b4f472e28..5978b94e0340 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -36,16 +36,7 @@ static DEFINE_MUTEX(set_freq_lock);
 /* Use 800MHz when entering sleep mode */
 #define SLEEP_FREQ      (800 * 1000)
 
-/*
- * relation has an additional symantics other than the standard of cpufreq
- * DISALBE_FURTHER_CPUFREQ: disable further access to target
- * ENABLE_FURTUER_CPUFREQ: enable access to target
- */
-enum cpufreq_access {
-        DISABLE_FURTHER_CPUFREQ = 0x10,
-        ENABLE_FURTHER_CPUFREQ = 0x20,
-};
-
+/* Tracks if cpu freqency can be updated anymore */
 static bool no_cpufreq_access;
 
 /*
@@ -182,12 +173,10 @@ static unsigned int s5pv210_getspeed(unsigned int cpu)
         return clk_get_rate(cpu_clk) / 1000;
 }
 
-static int s5pv210_target(struct cpufreq_policy *policy,
-                          unsigned int target_freq,
-                          unsigned int relation)
+static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
 {
         unsigned long reg;
-        unsigned int index, priv_index;
+        unsigned int priv_index;
         unsigned int pll_changing = 0;
         unsigned int bus_speed_changing = 0;
         int arm_volt, int_volt;
@@ -195,9 +184,6 @@ static int s5pv210_target(struct cpufreq_policy *policy,
 
         mutex_lock(&set_freq_lock);
 
-        if (relation & ENABLE_FURTHER_CPUFREQ)
-                no_cpufreq_access = false;
-
         if (no_cpufreq_access) {
 #ifdef CONFIG_PM_VERBOSE
                 pr_err("%s:%d denied access to %s as it is disabled"
@@ -207,27 +193,13 @@ static int s5pv210_target(struct cpufreq_policy *policy,
                 goto exit;
         }
 
-        if (relation & DISABLE_FURTHER_CPUFREQ)
-                no_cpufreq_access = true;
-
-        relation &= ~(ENABLE_FURTHER_CPUFREQ | DISABLE_FURTHER_CPUFREQ);
-
         freqs.old = s5pv210_getspeed(0);
-
-        if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
-                                           target_freq, relation, &index)) {
-                ret = -EINVAL;
-                goto exit;
-        }
-
         freqs.new = s5pv210_freq_table[index].frequency;
 
-        if (freqs.new == freqs.old)
-                goto exit;
-
         /* Finding current running level index */
         if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
-                                           freqs.old, relation, &priv_index)) {
+                                           freqs.old, CPUFREQ_RELATION_H,
+                                           &priv_index)) {
                 ret = -EINVAL;
                 goto exit;
         }
@@ -559,16 +531,18 @@ static int s5pv210_cpufreq_notifier_event(struct notifier_block *this,
 
         switch (event) {
         case PM_SUSPEND_PREPARE:
-                ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
-                                            DISABLE_FURTHER_CPUFREQ);
+                ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
                 if (ret < 0)
                         return NOTIFY_BAD;
 
+                /* Disable updation of cpu frequency */
+                no_cpufreq_access = true;
                 return NOTIFY_OK;
         case PM_POST_RESTORE:
         case PM_POST_SUSPEND:
-                cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
-                                      ENABLE_FURTHER_CPUFREQ);
+                /* Enable updation of cpu frequency */
+                no_cpufreq_access = false;
+                cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
 
                 return NOTIFY_OK;
         }
@@ -581,18 +555,18 @@ static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
 {
         int ret;
 
-        ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
-                                    DISABLE_FURTHER_CPUFREQ);
+        ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
         if (ret < 0)
                 return NOTIFY_BAD;
 
+        no_cpufreq_access = true;
         return NOTIFY_DONE;
 }
 
 static struct cpufreq_driver s5pv210_driver = {
         .flags          = CPUFREQ_STICKY,
         .verify         = cpufreq_generic_frequency_table_verify,
-        .target         = s5pv210_target,
+        .target_index   = s5pv210_target,
         .get            = s5pv210_getspeed,
         .init           = s5pv210_cpu_init,
         .name           = "s5pv210",